It’s Conservation Week – a good time for backyard pest detection

17 September 2018

Mimosa tree Carl Lewis

It was backyard detective work that spurred Mimi Olds-Spence, of Auckland, to get active in conservation some months ago.

She noticed that her beloved silk tree was being decimated. Something was eating the flowers and leaves, strewing the ground with fragments and breaking branches – all typical signs of possum browse. Droppings confirmed the culprit. There were other signs too.

“In feijoa season the possums would take fruit up onto the roof to eat and drop bits, which then clogged the guttering,” Mimi says. “Next door, the possums ate the plum tree blossom every year and they love the Indian bead tree too; eating the leaves, flowers and then the seeds,”

Mimi got a Timms trap. Eight months and 22 possum kills later, she began to wonder if she would ever win. The possums kept coming, even though she lives in an urban area just seven minutes’ drive from the centre of Auckland city.

In desperation, she went to a trap handout being run by the Eastern Bays Songbird Project, a community-led conservation group dedicated to restoring native ecosystems from Orakei to Glendowie. She put her name down. Not long after, John Laurence from the songbird project visited, looked over the lay of the land and then returned with possum and rat traps, supplied by Auckland Council, to install in the wider area – especially along the edge of a bush area from where new possums were probably coming from. That, in turn, led to Mimi taking on the role of area co-ordinator in her local Reihana Street Valley of Okahu Bay.

She hopes local trees will benefit from the rat trapping as well as possum trapping. She had noticed, for instance, that rats ate the fruit from nearby guava trees even though the possums appear uninterested.

“I’m hopeful we may see the end of the possums yet,” she says. “I’ve noticed that since we caught our twenty-two possums, the plum tree next door finally has flowers that are not being eaten and although it’s still early for the silk tree to leaf up, we might finally see it in full bloom this summer. That would be great for the tui.”

Photograph: Foliage and flowers of a silk tree (or mimosa), which possums love to browse on. By Carl Lewis [CC BY 2.0, via Wikimedia Commons]